Railway switch circuit controller



Sept. 8, 1936. i c, R, BEALL 2,053,891

RAILWAY SWITCH CIRCUIT CONTROLLER Filed May 24, 1935 2 Sheets-Sheet 1 7Fly 6.

INVENTOR libarles R. Beall,

HE ATTORNEY Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE RAILWAYSWITCH CIRCUIT CONTROLLER Application May 24, 1935, Serial No. 23,292

17 Claims.

My invention relates to railway switch circuit controllers, andparticularly to circuit controllers of the type known as heavy dutycircuit controllers.

Circuit controllers embodying my invention are particularly suitablefor, although in no way limited to, use in connection with manuallyoperated switches which are installed on electrified roads in traincontrol territory at locations where a track circuit extends for aconsiderable distance in both directions from the switch, and theirfunction is to provide train control protection by short circuiting thetrack circuit whenever the switch is moved away from its normal positionby the switch throwing and locking mechanism, or by a train trailing theswitch.

A principal object of my invention is to provide novel means foroperating the circuit controller to cause it to shunt the associatedtrack circuit when a train trails the switch.

I will describe one form of circuit controller embodying my invention,and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a top plan view showing a switchA operated by a switch throwing and locking mechanism 13 provided with acircuit controller C constructed in accordance with my invention. Fig. 2is an enlarged top plan view with cover removed of the circuitcontroller C shown in Fig. 1. Fig. 3 is an enlarged view, partly in sideelevation and partly in section, of the circuit controller C shown inFig. 1, together with a portion of the operating mechanism B. Figs. 4and 5 are sectional views taken on the lines IVIV and V--V,respectively, of Fig. 2. Fig. 6 is an enlarged top plan view of therocker arm I2 forming part of the circuit controller illustrated inFigs. 2 and 3. Fig. '7 is an enlarged top plan view of the contactoperating member I3 forming part of the circuit controller shown inFigs. 2 and 3. Fig. 8 is a left-hand end view of the latching member 40forming part of the circuit controller illustrated in Figs. 2 and 3.

,Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. 1, the reference character A designates arailway switch comprising, as usual, two fixed rails I and I00** and twomovable rails or switch points IM and IOI The fixed rails I00 and I00are laid on tie plates I03 and are secured to cross ties I04 in theusual manner. The movable rails IN and I0I are rod I 06, and may bemoved into a normal or a reverse position by means of a switch operatingmechanism B which is connected with the head rod I06 through the mediumof a throw rod I01 and a switch basket I08. When the switch occupies itsnormal position, in which position it is shown in the drawings, themovable rail IOI engages the fixed rail I00, and the movable rail I0 Iis spaced a slight distance from the fixed rail I00. When the switch isreversed, however, the movable rail IOI then engages the fixed rail I00,and the movable rail IN is spaced from the fixed rail I00.

The mechanism B forms no part of my present invention, and may be of anysuitable type. As here shown, this mechanism is similar to thatdescribed and claimed in Letters Patent of the United States No.1,654,023, granted to C. C. Thorn, on December 27, 1927, and since thismechanism forms no part of my present invention, only those partsthereof which are essential to a clear understanding of my presentinvention have been illustrated in detail in the drawings and will bedescribed herein. Referring particularly to Fig. 3, the portion of themechanism here illustrated comprises a locking plunger which is slidablymounted in a longitudinally extending groove 6 formed in the tail-likeextension 3 of the housing 4 of the mechanism. This locking plunger issecured at its right-hand end to the motion plate I of the mechanism andcooperates at its left-hand end with a lock rod L which is attached tothe front rod I05 of the switch A. When the switch A and switch throwingand looking mechanism B both occupy their normal positions, the plunger5 occupies the position shown, and when in this position, it enters apair of aligned notches 8 in the lock rod L, thus securely locking theswitch in its normal position. When, however, the switch throwing andlocking mechanism is operated to its reverse position to move the switchto its reverse position, the locking plunger is moved toward the rightto a retracted position, the parts being so proportioned that theplunger will be moved toward its retracted position far enough towithdraw the locking plunger from engagement with the notches 8 andunlock the switch before any movement of the movable rails of the switchtakes place. When the switch throwing and locking mechanism issubsequently restored to its normal position to restore the switch toits normal position, the locking plunger 5 will not start to enter thenotches 8 until after the switch has reached its full normal position.If a fuller description of the construction and operation of the switchthrowing and locking mechanism is desired, reference may be had to thepreviously referred to Thorn patent.

The circuit controller embodying my present invention, which circuitcontroller is designated as a whole by the reference character C, isenclosed in an auxiliary casing I which is secured to the tail-likeextension 3 of the casing 4 of the mechanism B. The casing I is closedat its upper end by a hinged cover 2, and has formed in the bottomthereof directly above the locking plunger 5, a longitudinally extendingslot 9. A transversely extending pin II (see Figs. 3 and 4) is mountedin two aligned lugs III which project upwardly from the bottom of thecasing I on opposite sides of the slot 9, and pivoted on this pin is arocker I2 and a contact operating member I3.

The rocker I2 is an irregularly shaped casting or forging and, as bestseen in Fig. 6, is provided at one end with a slotted tail-likeprojection I2, and at the other end with two spaced arms I2 and I2having outwardly and upwardly extending offset portions I2 and I2 whichare connected together at their upper ends by an integral web I2. Aroller I4 is rotatably mounted within the slot in the tail-likeprojection I 2 and a second roller I5 is rotatably mounted between thearms I2 and I2. The rollers I4 and I5 cooperate with a cam I6 secured tothe locking plunger 5 in such manner that, when the locking plungeroccupies its locking position in which it is shown in the drawings, therocker will be positively rotated in a clockwise direction to an extremeposition which I shall term its normal extreme position, but that, whenthe locking plunger is moved from its locking position to its retractedposition, the rocker will then be rotated in a counter-clockwisedirection from its normal extreme position to an intermediate extremeposition before the locking plunger has been moved far enough to clearthe lock rod, and that, as soon as the locking plunger has been movedfar enough to clear the lock rod, the rocker will then be rotated in acounter-clockwise direction from its intermediate extreme position towhat I shall term a reverse" extreme position. The taillike projectionI2 of the rocker is so constructed that, when the rocker occupies itsnormal position, there will be only a relatively small amount ofclearance between the tip of this extension and the upper side of thelocking plunger 5. The reason for this construction will be made clearhereinafter.

The contact operating member I3 is also an irregularly shaped casting orforging and, as shown in Fig. '7, this operating member comprises twoside members I3 and I3 which straddle the rocker I2 at the pivot pin II.The side members I3 and I3 are provided at one end with upwardlyextending offset portions I3 and I3 respectively, (see Figs. 2, 3 and 4)and are connected together at their opposite ends by an integral plateI3'. The side members I3 and I3 are also connected together intermediatetheir ends by a cross member I3.

An insulating block I1 is secured intermediate its ends to the underside of the plate I3 of the contact operating member I3, and attached tothis block adjacent its opposite ends are two U-shaped switch elementsI8 and I9 (see Fig. 5). The legs I8" and I3 of the switch element I8 actas switch blades and cooperate respectively with slotted switch jaws 20*and 20 of the usual and well-known type. The legs I9 and I9 of theswitch elements I9 likewise act as switch blades and cooperaterespectively with slotted switch jaws 2I and 2I' which latter jaws aresimilar to the jaws 20 and 20 The jaws 20, 20 2 I and 2I are secured insuitable spaced relation to an insulating block 22 which is bolted tothe bottom of the casing I. Formed integral with the switch blades 20,20 2I* and 2I respectively, are conducting bars 23, which bars extendwith considerable clearance through slots 24 formed in the end wall ofthe casing I, and carry at their outer end terminal connectors 25. Theconducting bars are maintained in the desired spaced relation by meansof a notched insulating member 48 which is secured to the end wall ofthe casing I, and the notches of which receive the bars relativelysnugly. The contact operating member I3 is movable between an openposition in which it is shown in the drawings, and a closed position inwhich stop lugs 21 formed on the side members I3 and I3 at the oppositeends of the cross member I3 engage stop lugs 28 formed on the easing I.When the contact operating member occupies its open position the switchblades are out of engagement with the associated switch jaws, and underthese conditions the contacts of the circuit controller are open. When,however, the contact operating member I3 occupies its closed position,the switch blades then engage the associated switch jaws and thecontacts of the circuit controller are closed.

The contact operating member I3 is operatively connected with the rockerI2 by means of spring mechanism comprising two eyebolts 30 and 3|, theeyes of which are loosely pivoted on the opposite ends of a horizontalrod 32 which is mounted in the upper ends of the offset portions I3 andI3 of the contact operating member I3. The shanks of the eyebolts 30 and3| extend with considerable clearance through holes I2 and I2 providedin an upright member I2 which is formed on the rocker I2 directly abovethe pivot pin II, and have slidably mounted thereon, between the uprightmember I2 and nuts 41 which are adjustably screwed onto the threadedouter ends of the shanks, spring sleeves 34 and 33, respectively. Thespring sleeve 33 is provided at the end adjacent the associated nut 41with an annular flange 33, and is surrounded by a compressed coil spring35, one end of which engages the flange 33, and the other end of whichengages the upright member I2 The spring sleeve 34 is similarly providedat the end adjacent the associated nut 41, with an annular flange 34,and is surrounded by a compressed coil spring 36, one end of whichengages the fiange 34, and the other end of which engages the uprightmember I2 The nuts 41 are so adjusted that, when the rocker occupies itsnormal position and the contact operating member occupies its openposition, there will be a small amount of clearance between the springsleeves 33 and 34 and bosses 38 which are provided on the upright memberI 2 to center the adjacent ends of the springs, and the parts are soproportioned that the springs will constantly bias the operating memberto its closed position in all positions of the rocker.

The circuit controller also comprises a latching member 40 which ispivotally suported on a rod 4I mounted in the ofl'set portions I2 and I2of the rocker I 2 at the lowermost part of these ofl'set portions. Thelatching member 40 is provided with an upwardly extending latching arm40,

and with a depending latch foot 40 and is constantly biased to alatching position by means of acompressed coil spring 44, one end ofwhich engages the arm 40, and thetother end of which engages the web I2of the rocker l2 within a circular recess45'formed in the web H. Thespring 44 is prevented from jumping out of place at the end whichengages the arm 40 by means of a boss 40.(see Fig. 8) which is providedon the arm, and the other end of the spring is prevented from jumpingout of place by a screw 46 which is screwed through the web I! of therocker l2 and extends part way into the spring. A notch 4ll is formed inthe upper end of the arm 40, and this notch cooperates with a latchcatch 5| which is adjustably screwed through the cross member I3 of thecontact operating member l3. The latch catch 5| is locked in itsadjusted position by means of a lock nut 52.

The latching foot 4|| carries a roller 42 which cooperates with anannular notch 43 formed in a point detector rod D. The point detectorrod D is slidably mounted in suitable guides formed in the sides of thecasing I, and is secured to the movable switch point of the switch A.

The parts are so designed and so adjusted that the latch catch willenter the notch 40 when and only when the latching member occupies itslatching position, and that, when the latch catch 5| is in the notch 40movement of the rocker l2 between its normal and intermediate positionswill cause the contact operating member l3 to move between its open andclosed positions in substantially the same manner as if the contactoperating member and rocker were rigidly secured together iormovement asa unit. The parts are Iurther so proportioned that. when the rocker ismoved to its normal position, the latching member 40 will remain in itslatching position if and only if the roller 42 has then fully enteredthe notch 43 in the lock rod D, and that the roller 42 will fully enterthe notch 43 when and only when the switch points are in their fullnormal positions and the then closed point |0| is in proper engagementwith the associated fixed rail Hill. The parts are further soproportioned that movement of the rocker to its full reverse positionwill cause suflicient relative movement of the rocker and contactoperating member, in opposition to the bias of the biasing springs 35and 35, so that if the latch catch 5| is out of engagement with thenotch 40 in the latching member 40 prior to this movement, the latchwill automatically move to the position in which the latch catch entersthe notch.

A coil spring 55 is stretched between a lug I3 formed on the arm l3 ofthe contact operating member l3 and a pin 56 which is riveted to theside of the casing I; and a similar spring 51 is stretched between a lug|3 formed on the arm I3 of the contact operating member l3 and a pin 58which is riveted to the side of the casing The function of the springs55 and 51 is to minimize vibration of the parts due to the passage oftrains over the switch when the parts of the circuit controller occupythe positions in which they are shown in the drawings.

The operation of the circuit controller, as a whole, is asfollows: Whenthe switch A occupies its normal position and is properly locked in thisposition by the locking plunger 5, all parts of the circuit controllernormally occupy the positions in which they are shown in Figs. 2 and 3.That is to say, the rocker I2 is held in its normal position byengagement of the roller l5 with the cam IS, the

latching member '40 occupies its latching position, and the contactoperating member I3 is held in its normal position is opposition to thebias of the springs 35 and 36 of the biasing mechanism by engagement'ofthe latch catch 5| with the notch 40 in the arm 40* of the latchingmember 40. If, now, with the parts in the positions just described, theswitch throwing and locking mechanism is operated 'to reverse theswitch, the rocker l2 will be rotated to its intermediate positionbefore the locking plunger 5 has been moved toward its retractedposition far enough to withdraw it from the notches 8 in the lock rod Land unlock the switch, and as soon as the locking plunger 5 has been:moved far enough to withdraw it from the notches 8 and unlock theswitch, the rocker will then be rotated to its full retracted positionand will be subsequently held in its retracted position during thebalance of the operation of the switch throwing and locking mechanism.The movement of the rocker I2 to its intermediate position will cause aforce to be transmitted to the contact operating member l3 through thesprings 35 and 38 of the biasing mechanism, which force, due to thepreviously pointed out proportioning of the parts, will cause thecontact operating member to move to its closed position and therebyclose the contacts of the circuit controller. When the contact operatingmember reaches its closed position, the lugs 21 will move intoengagement with the stops 28, and will thus prevent further movement ofthe contact operating member. As a result, the movement of the rockerwhich takes place when the locking plunger 5 becomes withdrawn from thenotches 8 in the lock rod L will compress the springs 35 and 36 beyondtheir initial compression, and will cause the latching member 40 to moveto a position in which the bottom of the notch 40 is out of engagementwith the latch catch 5|, but in which the vertical side of the notch 40is still in engagement with the face of the latch catch. After therocker l2 has been moved to its full reverse position, the parts willremain in the positions which they then occupy as long as the switchthrowing and locking mechanism remains in the position corresponding tothe reverse position of the switch. It should be noted that since themovement of the rocker |2 to its intermediate position takes placebefore the switch points start to move, when the lock rod L moves due tothe resultant movement of the switch points, the roller 42 will thenhave been rotated to a position in which it is out of engagement withthe notch 43 in the lock rod, and it will be seen, therefore, that themovement of the lock rod will have no effect on the circuit controllerunder these conditions.

When the switch has been moved to its reverse position by the switchthrowing and locking mechanism, and this mechanism is subsequentlyoperated to restore the switch to its normal position, the operation ofthe various parts of the circuit controller will be the reverse of thatjust described, and it is believed that this operation will be readilyunderstood from the foregoing without further description.

I will now assume that the parts are in the positions in which they areshown in the drawings, and'that the point detector rod is movedlongitudinally toward the left as viewed in Fig. 1, due for example, toa train trailing the switch. Under these conditions, the movement of thepoint detector rod will force the roller 42 out of the notch 43 thuscausing the latching member 40 to move to-an unlatching position inwhich the notch 40 is out of engagement with the latch catch 5|. Whenthe latch catch moves to its unlatching position, the springs 35 and 36of the biasing mechanism will drive the contact operating member |3 toits closed position, thereby closing the contacts of the circuitcontroller. These contacts will then remain closed until the parts arerestored to their normal latched positions in which they are shown inthe drawings. This can be done either by opening the hinged cover 2 andmanually raising the contact operating member 3 to its normal position,or by operating the switch throwing and locking mechanism from itsnormal position to its reverse position and back to its normal position,provided that the notch 43 in the point detector rod D is then inalignment with the roller 42, as will be the case if the switch has notbeen damaged. It should be noted that when the parts are restored totheir normal positions by manually raising the contact operating member|3, the tail piece l2 will cooperate with the locking plunger 5 toprevent counterclockwise rotation 01 the rocker l2 due to the forcewhich is transmitted to the rocker through the springs 35 and 36 of thebiasing mechanism, thus making it possible to secure the necessarydisplacement between the contact operating member I3 and rocker |2 topermit the latch catch 5| to enter the notch 40 in the latching member40. It should also be noted that as soon as the necessary displacementhas been obtained, the spring 44 will automatically move the latchingmember 40 to its latching position. It should further be noted that whenthe parts are restored to their normal positions by moving the switchthrowing and locking mechanism to its reverse position and back to itsnormal position, the previously described movement of the rocker |2 toits full reverse position which takes place as soon as the switchthrowing and locking mechanism has been moved toward its reverseposition far enough to unlock the switch, automatically causes thenecessary displacement of the contact operating member I3 and rocker |2to permit the spring 44 to restore the latching member to its latchingposition. It will be obvious, of course, that if the switch has beendamaged by a trailing train a suflicient amount so that the pointdetector rod is prevented from returning to the position in which thenotch 43 aligns with the roller 42, the latching member 40 will beprevented from moving to its latching position until the switch has beenrepaired.

When a switch is improperly trailed in the manner just described, itsometimes happens that the switch points are damaged sufliciently tomake it undesirable to permit trains to move over the switch, but that,due to the resiliency of the parts, the point detector rod will springback to its original position, after the train has passed the switch,far enough so that the latching member can be restored to its latchingposition. However, when this condition exists,- the parts will usuallybe distorted sufliciently, so that, if the switch is once unlocked, itwill be impossible to relock it until the switch has been repaired. Witha circuit controller embodying my invention it is contemplated that thecircuit controller casing will be locked by a lock to which only themaintainer will have a key, thus making it necessary for any resettingwhich is done by trainmen to be done by operating the switch throwingand locking mechanism in the manner previously described, and since thismethod of resetting the circuit controller necessitates unlocking theswitch, it will be seen that an added degree of protection is obtained.

It may in some instances be desirable to prevent resetting of the switchexcept by having the maintainer manually raise the contact operatingmember l3, and when this is the case, this result can be obtained byremoving the highest portion of the cam I6. When this is done, theoperation of the apparatus will be similar to that just described exceptthat the rocker |2 will only be moved between its normal position andthe position which I have termed its intermediate position in theforegoing description, thus making it impossible to reset the circuitcontroller by operation of the switch throwing and locking mechanism.

It follows from the foregoing that a circuit controller embodying myinvention causes a deflnite indication to be given when a switch istrailed by a train regardless of the extent of damage to the switch, andthat this indication will continue to be given until the propermaintainer arrives at the switch to inspect it, and if necessary repairit, thus precluding the possibility of a dangerous condition existing atany time due to a train trailing the switch.

It should be pointed out that the tail piece |2 of the rocker H3 inaddition to cooperating with the locking plunger 5 to make possible themanual restoration of the parts to their normal positions after a trainhas trailed the switch in the manner described, also cooperates with thelocking plunger to prevent the parts from vibrating sufficiently to movethe latching member to its unlatching position in the event that thesprings 55 and 57 should fail to prevent vibration of the parts for anyreason, as might happen if these springs should break.

It will be readily understood that it is desirable to be able to locatea circuit controller of the type described on either side of the switchwith which it is adapted to be used, and to be able to use the circuitcontroller with either a right-hand or a left-hand switch. In order topermit this to be done without the provision of right and left-handparts, the latching member 40 has been so constructed that it may beturned end for end on the pin 4|, and the latching arm 4|? has beenprovided in the side opposite to the notch 40 with a notch 4t! which issimilar to the notch 40, and which, when the latching member 40 isturned end for end, cooperates with the latch catch 5| in the samemanner that the notch 40 cooperates with the latch catch 5| when thelatching member occupies the position in which it is shown in thedrawings. Furthermore, the latching arm 40 has been provided on the sideopposite to the boss 40 with a similar boss 40, which latter bosscooperates with the spring 44 to maintain this spring in the properposition when the latching member 40 is turned end for end from theposition shown. The operation of the circuit controller as a whole whenthe latching member is turned end for end is similar to that previouslydescribed, it being understood that under these conditions the notch 43in the lock rod D would occupy the proper position to properly cooperatewith the roller 42.

Although I have herein shown and described only one form of circuitcontroller embodying my invention, it is understood that various changesand modifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway switch, a contact which is biased to aclosed position, means for normally latching said contact in an openposition when said switch occupies one extreme position, and means fortripping said latch to permit said contact to move to its closedposition if a train trails the switch when the switch occupies said oneextreme position.

2. In combination, a railway switch, a member biased to one position,means for normally latching said member in another position when saidswitch occupies one extreme position, means for operating said latchingmeans to release said member if a train trails the switch when theswitch occupies said one extreme position, and contacts controlled bysaid member.

3. In combination, a railway switch, a member biased to one position,means for normally holding said member in another position in oppositionto its bias when said switch occupies one extreme position, means forreleasing said member if a train trails the switch when said switchoccupies its one extreme position, and contacts controlled by saidmember.

4. In combination, a railway switch, means for locking said switch inone extreme position, a member biased to one position, means fornormally holding said member in another position in opposition to itsbias when said switch is locked in said one extreme position, means forreleasing said member if a train trails said switch when said switch islocked in said one extreme position, and contacts controlled by saidmember.

5. In combination, a railway switch, means for locking said switch inone extreme position, a contact biased to a closed position, means fornormally retaining said contact in an open position in opposition to itsbias when said switch is locked, and means for releasing said contact topermit it to be moved to its closed position if a train trails theswitch when it is locked.

6. In combination, a railway switch, means for locking said switch inone extreme position, a first member biased to one position, a latchingmember normally efiective to hold said first member in another positionin opposition to its bias when said switch is locked in said one extremeposition, a point detector rod secured to said switch, means controlledby said point detector rod for operating 3 said latching member torelease said first member if a train trails the switch when said switchis locked in said one extreme position, and contacts controlled by saidfirst member.

7. In combination, a railway switch, a lock rod secured to the switchpoints to move therewith and provided with a notch, a locking plungermovable into and out of engagement with said notch when and only whenthe switch occupies its extreme normal position, means for moving saidlocking plunger into and out of engagement with said notch, a contactoperating member movable between two positions and biased to oneposition, means including latching mechanism for normally holding saidcontact operating member in its other position when said locking plungeris in said notch, a point detector rod secured to said switch andcooperating with said latching mechanism to trip said latchingmechanisrnand release said contact operating member if a train trailsthe switch when said locking plunger is in said notch, and contactscontrolled by said contact operating member.

8. A circuit controller comprising a casing, a rocker and a contactoperating member pivotally supported in said casing for rotation about acommon axis, means for moving said rocker between two positions, springmechanism for operatively connecting said contact operating member andsaid rocker in such manner that said contact operating member isconstantly biased to one position, latch mechanism effective for attimes latching said contact operating member in another position inopposition to the bias of said spring mechanism when said rocker ismoved to one position, and a point detector rod slidably mounted in saidcasing and cooperating with said latch mechanism for at times operatingsaid latch mechanism to release said contact operating member.

9. In combination, a railway switch, a switch throwing and lockingmechanism for operating said switch, a contact biased to a closedposition, means controlled by said switch throwing and latchingmechanism and including a latch for normally latching said contact in anopen position when said switch is moved to one extreme position, andmeans for tripping said latch if a train trails the switch when saidswitch occupies said one extreme position.

10. In combination, a railway switch, a lock rod secured to the switchpoints to move therewith and provided with a notch, a switch throwingand locking mechanism for moving said switch between its two extremepositions, said mechanism being provided with a locking plunger whichenters the notch in said lock rod when said switch is moved to oneextreme position by said mechanism to lock said switch in said oneextreme position, an auxiliary casing secured to said mechanism, apivoted rocker in said auxiliary casing controlled by said lockingplunger in such manner that said rocker will be moved to one extremeposition when said locking plunger is fully within the notch in saidlock rod and to another position before the locking plunger becomeswithdrawn from the notch in said lock rod, a contact operating memberpivotally supported in said casing and operatively connected with saidrocker by spring mechanism in such manner that said contact operatingmember is constantly biased to one position, a latching member in saidcasing normally effective to hold said contact operating member inanother position in opposition to its bias when said rocker occupies itsone extreme position, and a point detector rod secured to the switchpoints and cooperating with said latching member in such manner thatsaid point detector rod will operate said latching member to releasesaid contact Operating member if a train trails the switch when theswitch occupies its one extreme position.

11. In combination, a railway switch, a locking plunger movable into andout of a locking position in which it engages a lock rod secured to saidswitch to lock said switch in an extreme position, a pivoted rocker,means for moving said rocker to one position when said locking plungeroccupies its locking position and to another position before said switchbecomes unlocked when said locking plunger is moved out of its lockingposition, a pivoted contact operating member operatively connected withsaid rocker in such manner that said contact operating member isconstantly biased to one position, latching mechanism normally effectivefor preventing said contact operating member from moving to its oneposition due to its bias when said rocker occupies its one position butnot when it occupies its other position, a point detector rod connectedwith said switch and cooperating with said latch mechanism in suchmanner that said point detector rod will operate said latching mechanismto permit said contact operating member to move to its one position dueto its bias if a train trails the switch while the switch is locked, andcon tacts operated by said contact operating member.

12. In combination, a railway switch, a lock rod secured to the switchpoints to move therewith and provided with a notch, a switch throwingand locking mechanism operatively connected with the switch, said switchthrowing and locking mechanism being provided with a locking plungerwhich is moved to a locking position in which it enters the notch insaid lock rod when said switch is moved to its one extreme position andto a retracted position in which said plunger is withdrawn from thenotch in said lock rod when said switch is moved to its other extremeposition, a pivoted rocker, means for moving said rocker to one extremeposition or another according as said locking plunger occupies itslocking position or its retracted position and to an intermediate.position when said locking plunger is moved away from its lockingposition but is still in engagement with said notch, a pivoted contactoperating member, biasing mechanism operatively connecting said rockerand said pivoted contact operating member and effective to constantlybias said contact operating member to one position, a latching memberpivotally secured to said rocker and biased to a latching position andprovided with a notch, a latch catch secured to said contact operatingmember and adapted to cooperate with said notch, the parts being soproportioned that said latch catch will occupy the notch in saidlatching member when and only when said latching member occupies itslatching position and that when said latch catch is in said notchmovement of said rocker between its one extreme position and itsintermediate position will move said contact operating member betweenanother extreme position and its one extreme position, a roller securedto said latching member, a point detector rod secured to one of thepoints of said switch and provided with a notch which receives saidroller when and only when said switch occupies said one extreme positionand said latching member occupies its latching position, and contactscontrolled by said contact operating member.

13. In combination, a railway switch, operating mechanism for movingsaid switch between its two extreme positions, a contact which is biasedto a closed position, means for normally latching said contact in anopen position when said switch is moved to one extreme position by saidoperating mechanism, and means for tripping said latch to permit saidcontact to move to its closed position if the switch points aredisplaced from said one position when said operating mechanism occupiesthe position corresponding to said one position.

14. In combination, a railway switch, operating mechanism for movingsaid switch between its two extreme positions, a contact which is biasedto a closed position, means for normally latching said contact in anopen position when said switch is moved to one extreme position by saidoperating mechanism, and means for tripping said latch to permit saidcontact to move to its closed position if the switch points are movedaway from said one position by means other than said switch operatingmechanism.

15. In combination, a railway switch, means for locking said switch inone extreme position, a member biased to one position, means fornormally holding said member in another position in opposition to itsbias when said switch is locked in said one extreme position, means forreleasing said member if said switch is moved away from said one extremeposition while it is locked in said one extreme position, and contactscontrolled by said member.

16. In combination, a railway switch having normal and reversepositions, switch operating mechanism having normal and reversepositions and operatively connected with said switch for moving saidswitch between its normal and reverse positions, a member biased to oneposition, means effective when and only when said switch occupies itsnormal extreme position and said switch operating mechanism occupies acorresponding extreme position for latching said member in anotherextreme position, and contacts controlled by said member.

17. A circuit controller comprising a casing, a contact operating memberbiased to one position in said casing, a point detector rod slidablymounted in said casing, means for latching said contact operating memberin another extreme position in opposition to its bias when and only whensaid point detector rod occupies a predetermined position, and contactscontrolled by said contact operating member.

CHARLES R. BEALL.

